This image shows a 3-tier cross-region deployment with Oracle Database on Oracle Cloud Infrastructure. There are two Oracle Cloud regions, a primary and a secondary, each with a VCN that contains a Load Balancer, 2 Availability Domains (AD1 and AD2), and 2 subnets (Subnet A and Subnet B). Information flows from an external DNS to the Load Balancer in each VCN.

In the primary region, Subnet A contains a Web Tier with a Node in AD1 and AD2. Information flows from the Load Balancer to each node in Web Tier. Subnet B has a standby database in AD1 and an active database in AD2. Information flows from the node in AD1 and AD2 to the active database. DataGuard sync flows from the active to the standby database.

In the secondary region, Subnet A contains a Web Tier with a Node in AD1 and AD2. Information flows from the Load Balancer to each node in Web Tier. Subnet B has a database in AD1. Information flows from the node in AD1 and AD2 to the database in AD1.

Cross-region DataGuard sync flows from the active database in the primary region to the database in the secondary region. Rsync information flows from the node in Primary AD2 to the node in Secondary AD1.